1. Field of the Invention
The present general inventive concept relates to a thermal inkjet printhead, an image forming apparatus having the same, and a method of manufacturing the thermal inkjet printhead.
2. Description of the Related Art
Generally, inkjet printers print a color image on a printing medium by ejecting ink droplets onto a desired region of the printing medium. Inkjet printers can be classified into shuttle type inkjet printers that perform printing jobs by moving a printing head in a processing direction of a printing medium and a perpendicular direction to the processing direction, and line printing type inkjet printers including printheads having a size corresponding to the width of a printing medium. Since line printing type inkjet printers perform printing jobs when the printheads are fixed and only the printing medium is processed, line printing type inkjet printers can print at high speed. Line printing type inkjet printers can include a single printhead or a plurality of printheads, having a length substantially corresponding to the width of printing paper. In this case, when the sum of the lengths of the plurality of printhead substantially corresponds to the width of printing paper, the plurality of printheads are referred to as an array type inkjet printhead.
Depending on the ink ejecting method, inkjet printheads can be classified into two types: thermal inkjet printheads and piezoelectric inkjet printheads. The thermal inkjet printhead generates bubbles in the ink to be ejected using heat, and ejects the ink using the expansion of the bubbles. On the other hand, the piezoelectric inkjet printhead ejects ink using a pressure generated by deforming a piezoelectric material.
The ink droplet ejecting mechanism of the thermal inkjet printhead will now be described in more detail. When a current pulse flows through a heater, the heater generates heat, and thus the ink adjacent to the heater is heated instantly to a temperature of about 300° C. Accordingly, the ink boils and generates bubbles, which expand and thus press the ink in an ink chamber. Therefore, the ink is ejected out of the ink chamber through nozzles in the shape of droplets.